Video of EssentialTremorLab Electrical Neurostimulation device

This first video is me recording my forearm tremor before applying the electrical neurostimulation.  I’ll run a Discrete Fourier Transform over this data to provide a snapshot of the spectrum of my tremors. 

Here is a rather longer video of the device in action edited down to leave out  the long gaps between the minutes. 

Apologies but the video is too large for blogger to upload so here is a link to it on YouTube

Here is the DFT of before:

and here is the DFT after 15 minutes of electrical neurostimulation.

Technical details and how to build your own device can be found here.

 #EssentialTremorLab

Photograph and description of our prototype

This photograph shows the current stimulus device and all the wiring and components.  A link to most of these components can be found in the parts list.  #9, #12, #13, #14a, and #14b have recommendations but you have the option to locally source these components.

1. Adafruit PyGamer.  I think the name is derived from Python-GameBoy. You can actually play games on it (and write your own games) but not at  the same time as you are running the tremor software.  The full specification can be found from the link in the parts lists.  All the cables are on sockets so no soldering!  Apologies for not powering it up so the LCD screen was easily visible. It also contains a rechargeable battery, and a Micro-SD slot for recording tremor data.
2. Is  a USB cable.  The end that plugs into the PyGamer is a Micro USB port.  Choose a cable that  will plug into your PC/Mac/Linux computer and has a Micro USB connector on the other end.  You will need this cable to load the tremor software onto the PyGamer.
3. 3a provides power and control to the Solid State Relays (10).  Red for power, Black for ground, and 2 white cables are the controller wires.  One white cable is part of the port/connector cable that supplied power and ground.  The other white cable comes from the other port.  3b is the power and ground from the second port and are not used.
4. Is the JST PH to JST SH Cable - STEMMA to QT / Qwiic - 200mm long.  This cable supplies power, ground, contro, and data to the Inertial Measurement Unit (IMU), since it is quite short, we have extended it via #5 and #7 to make it easy to use.
5. Is a Qwiic Adapted to allow us to connect a longer cable (#7) between the PyGamer and the IMU.
6. I made a mistake when labeling the image.  There is no #6.  Sorry!  ;-(
7. Is a 500mm Qwiic cable.  Sockets both ends so again, no soldering!
8. Is the IMU.  There are two options for this component in the parts list. One includes a magnetometer that is not used by the tremor device.  The IMU in the image is the one with the magnetometer.  It was the only one available at the time due to the worldwide silicon chip shortages.  Either IMU will work.  The IMU contains a 3 axis accelerometer and a 3 axis gyroscope.  This is the component that actually measures your tremor.
9. This is a cinch strap.  The IMU is sewn to this strap. It all looks rather mundane but it is quite important. A firm mount is a must to get good repeatable measurements of your tremor.  You need to be able to easily position the IMU on the back of your hand in the same position every day.  The cinch strap, as illustrated, can be adjusted for larger or smaller hands.  There is very little ‘give’ in the strap providing a firm base for the IMU. An alternative would be to use a glove and attach the IMU to it.
10. Are the Solid State Relays.  There is a pair of them. Under software control, these SSRs switch the electrical stimulation provided by the TENS Unit (#15),  between the Median and Radial nerves delivered via the electrodes #14a and #14b
11. #11a adn ##11b is the two sets of leads that are compatible with your TENS unit.  You need  two sets of these leads.  #11a is used to deliver the TENS stimulus to the SSRs (#10) and provides the ‘return path’ via electrode #13.  #11b supplies the TENS signal from the SSRs to the Median and Radial nerves via electrodes #14a and #14b.
12. Is a short jumper wire to connect the TENS output to both center taps of the SSRs.
13. Is the ‘return path’ electrode which should be attached to the back of the wrist.
14. ‘a’ and ‘b’ are the two electrodes that deliver the stimulus to the Radial and Median nerve.  These should be attached to the underside of the wrist.
15. TENS unit. Transcutaneous Electrical Nerve Stimulation (TENS) therapy involves the use of low-voltage electric currents to treat pain.  Because the TENS unit can produce a safe stimulus, it is used by the tremor device to stimulate the Radial and Medial nerve. 

Please Note: This device is not an FDA-approved system or device. The FDA’s responsibility is to regulate products on the commercial market and help safeguard the public. It’s not manufactured or sold anywhere in the world. It’s an open-source designed system that you can choose to build yourself. The FDA doesn’t currently regulate self experimentation. Individuals who build this device are essentially doing an (N=1) experiment, which they have a right to do by themselves, on themselves. If you decide to build anything described herein, you do so at your own risk.

(Please note: This information should not be used as a substitute for medical treatment and advice. Always consult a medical professional about any health-related questions or concerns.)

March 1 should be International Essential Tremor day!!!!

 First a little history: The familial Essential Tremor was first described by the German physician Georg Friedrich Most in 1836, while the term essential tremor (originally from the Italian language ‘tremore semplice essenziale’) was used for the first time in 1874 by the professor of medicine Pietro Burresi, who described the case of an 18-year-old man suffering from severe hand tremor while moving, as well as head tremor. In 1817, James Parkinson was the first to point out that ET was a disorder separate from Parkinson’s disease (PD), but his report was not published until 1887. A classic description of the disease was presented in 1925 by the Russian neurologist Lazar Salomonowicz Minor, after which ET is often also called ‘Minor’s disease’ 

Historical underpinnings of the term essential tremor in the late 19th century

https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC3461999/ 

It took until 2013 for Essential Tremors to receive its own medical classification identifier!  

The International Classification of Diseases-10th Revision-Clinical Modification (ICD-10-CM) ushers in, for the first time, a specific diagnostic code for essential tremor (“G25.0, essential tremor”). This milestone should not pass without comment. --Elan D Louis

From: The Lancet Neurology MARCH 01, 2013

The full description reads:

 2021 ICD-10-CM Diagnosis Code is  G25.0  Essential tremor (benign) 

…and that in my opinion is incorrect.  Benign Essential Tremors is an old and now obsolete term. I even doubt the veracity of the term “Essential” but that is the term the medico people use.

Essential: In medicine, of unknown cause… 

There is nothing benign about Essential Tremors. Essential Tremors has the potential to significantly disrupt daily activities and/or social interactions.

Transcutaneous Electrical Nerve Stimulation (TENS) of the Median and Radial nerve using COTS hardware (draft #1)

 JM Elek et al. described the attenuation of human wrist tremors by electrical stimulation in a paper in 1989. Recently the FDA approved a home use electrical stimulation device for the treatment of Essential Tremors (CALA Trio).  The technology behind this type of stimulation is well described and easily accessible from a large number of papers published by various authors during the past 30 years.  Having been introduced to the current generation of microcontrollers by an old acquaintance, I decided to investigate the feasibility of building an electrical stimulus device using Commercial Off The Shelf (COTS) hardware. It wasn’t a straight line path from early 2021 to this juncture.  It was an adventure in learning: both from reading and experimentation but that is a story for another time. 

Here are two photographs of my proof of concept stimulus device that I got working today, February 19, 2022.

This proof of concept test rig consists of a TENS unit I purchased from Amazon for about $100.  It has the advantage of being battery powered so it is portable and there are no dangerous voltages or currents involved.  My hand/arm tremors inspired me to deep dive into the research papers on Essential Tremors. All the online, freely accessible information, led me through a convoluted path that was littered with many interesting ideas and more than a few disappointments; "The best of the best (treatment) only works for about half of us ET sufferers!".  

Aside from the learning curve and the technical challenges, I wanted to see if it was possible to build an affordable device that was free from the substantial recurring costs of the commercial offering mentioned above.  Recurring costs are: a small amount of electricity necessary to charge the TENS unit and three round TENS self adhesive electrodes: cost about $0.50 each and they last a week or so. This "proof of concept" device is only the first step.  I have already started sourcing parts for the next version.  The control unit will be battery powered, portable, and will have a much simplified design.

The output of the TENS unit is switched between the Median nerve and the Radial nerve by a pair of Solid State Relays (SSR) seen next to my thumb.  The switching is controlled by an Arduino Mega 2690 microcontroller just above and to the left of my forefinger.  The Mega 2690 also measured the frequency of my tremors via a 3-axis gyroscope/accelerometer combo IMU mounted on a Velcro strip on the back of my hand.  Total cost was about $175 excluding taxes and shipping.

From my research, something like 40% of the ET population could benefit from this type of stimulation.  So I don’t yet know if this will attenuate my tremors in my forearm.  Whether or not I’m in that group will be discovered over the next couple of weeks of testing and adjustment.

AMA!

(Please note: This information should not be used as a substitute for medical treatment and advice. Always consult a medical professional about any health-related questions or concerns.)

Albuterol and Essential Tremors

I just had a complete Pulmonary Function Test (PFT).  The final part of the test started with four doses of Albuterol!  Yes, 4 doses!  Exhale, nurse dispenses, inhale, hold for 10 seconds.  Repeat 3 more times.

Then you have to wait for 10 minutes before the final test.  It’s all to see if bronco-dilators affect your lung capacity.

This is not my first experience with Albuterol. I’ve got a persistent dry cough which I’ve had for years.  Nothing cures it.  Some treatments make it  go away for a while.  Spring and sunshine helps sometimes.  Been prescribed Albuterol twice now.  Usually doesn’t do anything for the caught and usually doesn’t affect my mild Essential Tremors.

But this time it was different.  I felt a bit light headed as I left the medical centre.  I was OK to drive but by  the time I got home I had bad tremors. Worse than any I have experienced.  I had to use two hands to hold a small bowl of fruit while I ate.

I had visible tremors in my right hand, my non-dominant hand.  Usually, my tremors are only visible in my left hand.  My fingers in the right hand have started to develop some slight tremors over the past couple of years, but this was different.

My left arm tremors are Pronation/Supination tremors.  Known frequency of 5.2Hz with an amplitude of 2-3 centimetres.  Something like 2-3 on the TETRAS scale. Mild to moderate.

Today, the tremors in my right hand were just about as bad as what I normally experience in my left hand.

After two and a half hours, my tremors appear to be returning to my “normal” state.

A quick search of Pubmed, the National Library of Medicine shows a 1986 study shows Albuterol exacerbates Essential Tremors by as much as 50%. 

Caveat Emptor!  Another drug to be avoided or used sparingly with pre-knowledge that it may make one tremors worse.

Caprylic acid/Octanoic acid: A possible treatment for Essential Tremors

 Over on Reddit, sarazepeda wrote: “I’ve been taking caprylic acid, and don’t wanna jinx it… (I feel like right when something starts to help, it slowly stops helping)… but it’s been almost a week and a half now and the difference is astounding.”  

Now I’m very much ‘mainstream’ in regard to the treatment of Essential Tremors, but a quick google surprised me. Caprylic acid is more commonly known as Octanoic acid.  Wikipedia concluded its article with “Caprylic acid has been studied as part of a ketogenic diet to treat children with intractable epilepsy.[13] Caprylic acid is currently being researched as a treatment for essential tremor.[13][14]”.

[13] Dose-escalation study of octanoic acid in patients with essential tremor and [14] Octanoic acid in alcohol-responsive essential tremor which lead me to a study I had previously read, The Effect of Octanoic Acid on Essential Voice Tremor: A Double-Blind, Placebo-Controlled Study.

From [13] “Recently, 1-octanol has been shown to have efficacy in treating patients with essential tremor (ET). The primary metabolite of 1-octanol is octanoic acid (OA), which is now thought to be the active substance that mediates tremor suppression.”

All this leads me to a summary position: If your Essential Tremors are alcohol responsive, you can take Caprylic/Octanoic acid food supplements and get similar results without the downsides of actual alcohol consumption (maybe)!

Caveat Emptor: I am not a medical person. My background is STEM, in particular Electrical Engineering/Applied Physics.  I have been formally diagnosed with Essential Tremors. I actively research ETs and potential treatments. Do your own research and come to your own conclusions.

[13], the “Dose-escalation study of octanoic acid in patients with essential tremor” was a study to determine the “maximum tolerated dose”.  In this study they tested doses up to 128 mg/kg and found “most frequent AE (Adverse Event) was mild abdominal discomfort.” and “Secondary efficacy measures suggested a dose-dependent reduction of tremor.” Further, “Although our trial did not reach an MTD (maximum tolerated dose), a dose-dependent effect was demonstrated in the PK/PD (pharmacokinetics/pharmacodynamics) model as well as in secondary efficacy outcomes. Future studies are needed to explore the safety in higher dose ranges and to confirm dose-dependent efficacy in a placebo-controlled design.?

 “In conclusion, our results are promising for the development of OA (Octanoic Acid) as a treatment of ET.”

There you have it. It may be effective if your ETs respond to alcohol.  It’s a food supplement that is readily available at a reasonable price.

AMA: Ask Me Anything

What use is tremor measurements?

 On Reddit Temporal_Delusion writes: “Man reading your blog is pure depression fuel not gonna lie.”

Sorry that my blog depressed you.  My only intention with the blog was to offer information without the medical speak that can be confusing to understanding the problem we have.

TD: “Especially the one mentioning forearm and wrist tremors killing fine motor skills no matter what. Mine is also affecting the wrist movement (up down) and the forearm in the right hand mostly. Testing what you mentioned to be the wing beating position for the first time was dreadful.”

My back and forth rotation of the forearm tremor (pronation/supination) is relatively uncommon in the Essential Tremor population.  More common is the left/right movement of the hand (adduction/abduction).  The most common tremor in the hand/arm is the up/down (flexion/extension) tremor of the hand about the wrist joint. I use the wing beating position as I can provoke a visible tremor on demand making it easy to measure.

Action tremors, like when you move your hand to point at an object, are stronger than positional tremors such as the wing-beating position.  Eating soup with a spoon is also an action that can provoke a tremor.  Action tremors are more difficult to measure as you have to remove the ‘action’ component to see the tremor.  So I have a lot more work to do in measurement of my tremors.

TD: "It's sad to see that since this problem is relatively rare, there is pretty much no real help in the works one can hope for. I also got tinnitus which is very similar, a lot of anecdotal stuff that helps some, but not others. Once you exhaust the long list of "try this" "try that" and nothing changed, not for the better at least... hope is in short supply."

Essential Tremors are not relatively rare.  Learned studies suggest that perhaps as many as 5% of the general population has Essential Tremors.  Most of us don’t do anything about it and many general medical practitioners are not aware of it.  For all its prevalence, Essential Tremors did not have its own medical classification until 2013. Its ‘big brother’ Parkinson’s gets more attention. Even now, many Essential Tremor studies include references to Parkinson’s. The situation is improving and Essential Tremors is getting more research attention. We live in hope.

There is some, non-anecdotal stuff that helps with ETs. Propranolol, a common beta blocker, can suppress tremors in about 50% of the ET population.  There are other drugs that work for some but with a lower success rate and with more side effects.  If you have alcohol responsive tremors, 1 drink can give temporary relief.  The Cala Trio (very expensive) can give an hour or so relief after treatment for a slightly lower percentage of the ET population.

TD: I'm also somewhat of a realist about things, some call me a pessimist. At 25 years old, I've been on the decline for the past 5 despite best efforts on multiple fronts. The world is falling apart, I just wish I was older, that this happened in my 40s 50s or 60s where I could chalk it up as "expected".

It seems that Essential Tremors is different for each individual.  The progression of this condition is one area that is poorly studied. This is mainly due to two factors.  First in the world of scientific studies, it is “publish or perish”.  To study the prognosis of conditions like Essential Tremors takes time.  Time which could be used to conduct less time consuming studies and produce more published papers.  Secondly, at present, it is difficult and expensive to conduct a multi-year study of Essential Tremors as it requires a trained clinician to assess the severity of an individual's tremors. I was hoping to address some of the problems of tremor assessment with a multi-sensor device.

TD: What would you use your findings for? Even if you perfected the sensors and have all this data, what will you use it for? Aside from giving visual, quantified feedback on "how fucked we really are", I don't see where this is going.

Let me tell you a little story.

Once upon a time there was this retired IT/Software developer that liked to paint (pictures) and he decided to take an online drawing course; 7 lessons, each comprising three parts.  He failed to complete the first third of the first lesson because of tremors in his hand/forearm. 

He was super pissed off and after a while he went in search of a solution. Long story short: he "found" the Cala Trio but it cost $3200 + $156/month which was way beyond his budget and it doesn’t work for everyone.  Expensive but not technically challenging.  Also he found other "interesting" possible approaches to the treatment of Essential Tremors through electrical stimulation.

With the assistance of two fellow techies he finally settled on trying to do what Cala Health had done but with Commercial Off The Shelf technology. It wouldn't be pretty to look at but it should work and if it did it would only cost a small fraction of the Trio.  But how do you know if it is working?  You have to measure the tremor before and after. 

...and there you have it.  I need to be able to accurately, impartially, and consistently measure my tremors if I want to experiment with electrical simulation as a partial solution to my Essential Tremors.

AMA: Ask Me Anything

(Please note: This information should not be used as a substitute for medical treatment and advice. Always consult a medical professional about any health-related questions or concerns.)